i.MX6: add OTP support

Signed-off-by: Thilo Jeremias <tjeremias@de.adit-jv.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>

2 files changed, 247 insertions, 0 deletions

diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 271463cf14..b9cc103cd1 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -29,6 +29,7 @@ COBJS-$(CONFIG_ALI152X) += ali512x.o
 COBJS-$(CONFIG_DS4510)  += ds4510.o
 COBJS-$(CONFIG_FSL_LAW) += fsl_law.o
 COBJS-$(CONFIG_GPIO_LED) += gpio_led.o
+COBJS-$(CONFIG_IMX_OTP) += imx_otp.o
 COBJS-$(CONFIG_FSL_MC9SDZ60) += mc9sdz60.o
 COBJS-$(CONFIG_NS87308) += ns87308.o
 COBJS-$(CONFIG_PDSP188x) += pdsp188x.o
diff --git a/drivers/misc/imx_otp.c b/drivers/misc/imx_otp.c
new file mode 100644
index 0000000000..b4d129938e
--- /dev/null
+++ b/drivers/misc/imx_otp.c
@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) 2011 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/arch/sys_proto.h>
+
+#define BF(value, field)	(((value) << BP_##field) & BM_##field)
+#define DEF_RELAX 20
+
+#ifdef CONFIG_IMX_OTP_DEBUG
+#define log(a, ...) printf("[%s,%3d]:"a"\n", __func__, __LINE__, ## __VA_ARGS__)
+#else
+#define log(a, ...)
+#endif
+
+static int otp_wait_busy(u32 flags)
+{
+	int count;
+	u32 c;
+	struct iim_regs *otp = (struct iim_regs *)IMX_OTP_BASE;
+
+	for (count = 10000; count >= 0; count--) {
+		c = readl(&otp->ctrl);
+		if (!(c & (BM_OCOTP_CTRL_BUSY | BM_OCOTP_CTRL_ERROR | flags)))
+			break;
+	}
+
+	if (count < 0) {
+		printf("ERROR: otp_wait_busy timeout. 0x%X\n", c);
+		/* clear ERROR bit, busy bit will be cleared by controller */
+		writel(BM_OCOTP_CTRL_ERROR, &otp->ctrl_clr);
+		return -1;
+	}
+
+	log("wait busy successful.");
+	return 0;
+}
+
+static int set_otp_timing(void)
+{
+	u32 clk_rate;
+	u32 relax, strobe_read, strobe_prog;
+	u32 timing;
+	struct iim_regs *otp = (struct iim_regs *)IMX_OTP_BASE;
+
+	/* get clock */
+	clk_rate = mxc_get_clock(MXC_IPG_CLK);
+	if (clk_rate == -1) {
+		printf("ERROR: mxc_get_clock failed\n");
+		return -1;
+	}
+
+	log("clk_rate: %d.", clk_rate);
+
+	relax = clk_rate / (1000000000 / DEF_RELAX) - 1;
+	strobe_prog = clk_rate / (1000000000 / 10000) + 2 * (DEF_RELAX + 1) - 1;
+	strobe_read = clk_rate / (1000000000 / 40) + 2 * (DEF_RELAX + 1) - 1;
+
+	timing = BF(relax, OCOTP_TIMING_RELAX);
+	timing |= BF(strobe_read, OCOTP_TIMING_STROBE_READ);
+	timing |= BF(strobe_prog, OCOTP_TIMING_STROBE_PROG);
+	log("timing: 0x%X", timing);
+
+	writel(timing, &otp->timing);
+
+	return 0;
+}
+
+static int otp_read_prep(void)
+{
+	return  (!set_otp_timing()) ? otp_wait_busy(0) : -1;
+}
+
+#ifdef IMX_OTPWRITE_ENABLED
+static int otp_blow_prep(void)
+{
+	return  (!set_otp_timing()) ? otp_wait_busy(0) : -1;
+}
+
+static int otp_blow_post(void)
+{
+	struct iim_regs *otp = (struct iim_regs *)IMX_OTP_BASE;
+
+	printf("Reloading shadow registers...\n");
+	/* reload all the shadow registers */
+	writel(BM_OCOTP_CTRL_RELOAD_SHADOWS, &otp->ctrl_set);
+	udelay(1);
+
+	return otp_wait_busy(BM_OCOTP_CTRL_RELOAD_SHADOWS);
+}
+#endif
+
+static int fuse_read_addr(u32 addr, u32 *pdata)
+{
+	u32 ctrl_reg;
+	struct iim_regs *otp = (struct iim_regs *)IMX_OTP_BASE;
+
+	ctrl_reg = readl(&otp->ctrl);
+	ctrl_reg &= ~BM_OCOTP_CTRL_ADDR;
+	ctrl_reg &= ~BM_OCOTP_CTRL_WR_UNLOCK;
+	ctrl_reg |= BF(addr, OCOTP_CTRL_ADDR);
+	writel(ctrl_reg, &otp->ctrl);
+
+	writel(BM_OCOTP_READ_CTRL_READ_FUSE, &otp->read_ctrl);
+	if (otp_wait_busy(0))
+		return -1;
+
+	*pdata = readl(&otp->fuse_data);
+	return 0;
+}
+
+#ifdef IMX_OTPWRITE_ENABLED
+static int fuse_blow_addr(u32 addr, u32 value)
+{
+	u32 ctrl_reg;
+	struct iim_regs *otp = (struct iim_regs *)IMX_OTP_BASE;
+
+	log("blowing...");
+
+	/* control register */
+	ctrl_reg = readl(&otp->ctrl);
+	ctrl_reg &= ~BM_OCOTP_CTRL_ADDR;
+	ctrl_reg |= BF(addr, OCOTP_CTRL_ADDR);
+	ctrl_reg |= BF(BV_OCOTP_CTRL_WR_UNLOCK__KEY, OCOTP_CTRL_WR_UNLOCK);
+	writel(ctrl_reg, &otp->ctrl);
+
+	writel(value, &otp->data);
+	if (otp_wait_busy(0))
+		return -1;
+
+	/* write postamble */
+	udelay(2000);
+	return 0;
+}
+#endif
+
+/*
+ * read one u32 to indexed fuse
+ */
+int imx_otp_read_one_u32(u32 index, u32 *pdata)
+{
+	u32 ctrl_reg;
+	int ret = 0;
+	struct iim_regs *otp = (struct iim_regs *)IMX_OTP_BASE;
+
+	log("index: 0x%X", index);
+
+	if (index > IMX_OTP_ADDR_MAX) {
+		printf("ERROR: invalid address.\n");
+		ret = -1;
+		goto exit_nop;
+	}
+
+	enable_otp_clk(1);
+
+	if (otp_read_prep()) {
+		ret = -1;
+		printf("ERROR: read preparation failed\n");
+		goto exit_cleanup;
+	}
+
+	if (fuse_read_addr(index, pdata)) {
+		ret = -1;
+		printf("ERROR: read failed\n");
+		goto exit_cleanup;
+	}
+
+	if (*pdata == IMX_OTP_DATA_ERROR_VAL) {
+		ctrl_reg = readl(&otp->ctrl);
+		if (ctrl_reg & BM_OCOTP_CTRL_ERROR) {
+			printf("ERROR: read fuse failed\n");
+			ret = -1;
+		}
+	}
+
+exit_cleanup:
+	enable_otp_clk(0);
+exit_nop:
+	return ret;
+}
+
+#ifdef IMX_OTPWRITE_ENABLED
+/*
+ * blow one u32 to indexed fuse
+ */
+int imx_otp_blow_one_u32(u32 index, u32 data, u32 *pfused_value)
+{
+	int ret = 0;
+	struct iim_regs *otp = (struct iim_regs *)IMX_OTP_BASE;
+
+	enable_otp_clk(1);
+
+	if (otp_blow_prep()) {
+		ret = -1;
+		printf("ERROR: blow preparation failed\n");
+		goto exit_cleanup;
+	}
+
+	if (fuse_blow_addr(index, data)) {
+		ret = -1;
+		printf("ERROR: blow fuse failed\n");
+		goto exit_cleanup;
+	}
+
+	if (otp_blow_post()) {
+		ret = -1;
+		printf("ERROR: blow post operation failed\n");
+		goto exit_cleanup;
+	}
+
+	if (readl(&otp->ctrl) & BM_OCOTP_CTRL_ERROR) {
+		ret = -1;
+		printf("ERROR: OTP control\n");
+		goto exit_cleanup;
+	}
+
+	if (imx_otp_read_one_u32(index, pfused_value)) {
+		ret = -1;
+		printf("ERROR: OTP read\n");
+	}
+
+exit_cleanup:
+	enable_otp_clk(0);
+
+	return ret;
+}
+#endif